Novel photographic processes, compositions and products



United States Patent 3,230,086 NOVEL IHGTUGRAPHIC PROCESSES, COMPOSITIONS AND PRODUtITS Milton Green, Newton Center, Mass, assignor to iolaroid Corporation, Cambridge, Mass, a corporation of Delaware N0 Drawing. Filed Oct. 12, 1962, Ser. No. 230,287 39 Claims. (Cl. 96-29) This application is in part a continuation of my copending application, Serial No. 680,434, filed August 26, 1957, now abandoned.

This invention relates to photography and more particularly to products, compositions and processes for the development of photosensitive silver halide elements.

It is one object of the present invention to provide novel processes and compositions for the development of silver halide emulsions, in which colored developing agents are used to develop a latent image.

Another object is to provide novel processes and compositions for the development of silver halide emulsions, in which the novel developing agent is capable of developing a latent image and imparting a reversed or positive colored image of said latent image to a superposed image-receiving material.

A further object is to provide novel products, processes and compositions suitable for use in preparing monochromatic and multichromatic photographic images.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the processes involving the several steps and the relation and order of one or more of such steps with respect to each of the others, and the products and compositions possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

The novel photographic developing agents employed in this invention possess the properties of both a dye and a developing agent; thus they may be referred to as dye developers. The nature of these dye developers will be described hereinafter.

The photographic processes and compositions disclosed herein are particularly useful in the treatment of an exposed silver halide emulsion, whereby a positive dye image may be imparted to another element, herein referred to as an image-carrying or image-receiving element.

US. Patent No. 2,983,606, issued May 9, 1961, to Howard G. Rogers, discloses diffusion transfer processes wherein a photographic negative material, such as a photographic element comprising an exposed silver halide emulsion is developed in the presence of a dye developer to impart to an image-receiving layer a reversed or positive dye image of the developed image by permeating into said emulsion layer a suitable liquid processing composition and bringing said emulsion layer into superposed relationship with an appropriate image-receiving layer.

It is an object of this invention to provide additional dye developers suitable for use in such processes.

In carrying out the process of this invention, a photosensitive element containing a silver halide emulsion is exposed and wetted with a liquid processing composition, for example, by immersing, coating, spraying, flowing, etc., in the dark, and the photosensitive element superposed, prior to, during or after wetting, on an imagereceiving element. In a preferred embodiment, the photosensitive element contains a layer of dye developer, and the liquid processing composition is applied to the 3,23%,086 Patented Jan. 18, 1966 photosensitive element in a uniform layer as the photosensitive element is brought into superposed position with an image-receiving element. The liquid processing composition permeates the emulsion to provide a solution of dye developer substantially uniformly distributed therein. As the exposed silver halide emulsion is developed, the oxidation product of the dye developer is immobilized or precipitated in situ with the developed silver, thereby providing an imagewise distribution of unoxidized dye developer dissolved in the liquid processing composition. This immobilization is apparently, at least in part, due to a change in the solubility char? acteristics of the dye developer upon oxidation, and especially as regards its solubility in alkaline solutions. It also may be due, in part, to a tanning eifect on the emulsion by the oxidized developing agent. At least part of this imagewise distribution of unoxidized dye developer is transferred, by imbibiti-on, to a superposed image-receiving layer. Under certain circumstances, the layer of the liquid processing composition may be utilized as the image-receiving layer. The image-receiving layer receives a depthwise diffusion, from the emulsion, of unoxidized dye developer, without appreciably disturbing the imagewise distribution thereof, to provide a reversed or positive, colored image of the developed image. The image-receiving element may contain agents adapted to mordant or otherwise fix the diifused, unoxidized dye developer. If the color of the diffused dye developer is affected by changes in the pH of the image-receiving element, this pH may be adjusted in accordance with well-known techniques to provide a pH affording the desired color. Imbibition periods of approximately one minute have been found to give good results, but this contact period may be adjusted where necessary to compensate for variations in temperature or other conditions. The desired positive image is revealed by stripping the image-receiving element from the photosensitive element at the end of the imbibition period.

The dye developers of this invention may be utilized in the photosensitive element, for example in, on, or behind the silver halide emulsion, or they may be utilized in the image-receiving element or in the liquid processing composition. In a preferred embodiment, a coating or layer of the dye developer is placed behind the silver halide emulsion, i.e., on the side of the emulsion adapted to be located most distant from the photographed subject when the emulsion is exposed and preferably also adapted to 'be most distant from the image-receiving ele ment when in superposed relationship therewith. Placing the dye developer behind the emulsion layer, as in the preferred embodiment, has the advantage of providing increased contrast in the positive image, and also minimizes any light-filtering action by the colored dye developer. In this preferred embodiment, the layer of dye developer may be applied by using a coating solution containing about 0.5 to 8%, :by weight, of the dye developer. Similar concentrations may be used if the dye developer is utilized as a component of the liquid processing composition. In an especially useful mode of dispersing the dye developers in the photosensitive elements, the dye developer is dissolved in a water-immiscible solvent and then dispersed in a gelatin coating solution.

The liquid processing composition above referred to comprises at least an aqueous solution of an alkaline compound, for example, diethylamine, sodium hydroxide or sodium carbonate, and may contain the dye developer. In some instances, it may contain a minor amount of a conventional developing agent. It the liquid processing composition is to be applied to the emulsion by being spread thereon, preferably in a relatively thin, uniform layer, it may also include a viscosity-increasing compound constituting the film-forming material of the type which, when said composition is spread and dried, will form a relatively firm and relatively stable film. A preferred film-forming material is a high molecular weight polymer such as a polymeric, water-soluble ether inert to an alkali solution, as, for example, a hydroxyethyl cellulose or sodium carb-oxymethyl cellulose. Other filmforming materials or thickening agents Whose ability to increase viscosity is substantially unaffected when left in solution for a long period of time may also be used.

The novel dye developers of this invention may be represented by the formula:' V

wherein Ar is an aryl nucleus, such as a benzene or naphthalene nucleus; each Z is an alkoxy group, an alkyl group, preferably a lower alkyl group such as methyl or ethyl, or a halogen such :as chlorine; m is or1;uis0, 1,2 or3;vis0,1or2;pis1or2;Y is a p-dihydroxyphenyl, or a p-bis-acyloxyphenyl group; and X and X are each the radical of an az-o coupling component, which coupling component may be the same or different.

In a preferred embodiment the aryl nucleus is a benzene nucleus, and such dye developers may be represented by the formula:

wherein Y, Z, u, v. m. p, X and X have the same meaning as above.

As illustrations of suitable azo coupling components or couplers from which X and X may be derived, mention may be made of phenols and aromatic amines having a free position ortho or para to the hydroxyl or amino group, e.g., phenol, anilines, naphthols, anthrols, naphthylamines, etc.; heterocyclic aromatic compounds containing hydroxyl or amino groups, such as pyrazolones or pyrroles; aliphatic or alicyclic activated methylene couplers, i.e., compounds having an aliphatic or alicyclic methylene group activated by two adjacent keto,

aldehyde, ester or nitrile groups, which may be the same or different, or a keto, aldehyde, ester or nitrile group in combination with an amide group, e.g., 1,3-diketones or B-ketonic acid arylamides; etc., and substituted derivatives thereof. Examples of groups which may be present in such substituted derivatives include alkyl, sulfo, alkoxy, aryl, aryloxy, amino, keto, alkylamino, arylamino, hydroxyl, cyano, alkylamido, arylamido, carbalkoxy, carboxamido, sulfonamido, etc.

As used herein with reference to X and X the expression radical of a phenolic coupler is intended to refer to hydroxyphenyl, hydroxynaphthyl, hydroxyanthryl, etc. radicals, and substituted derivatives thereof; the expression radical of an aromatic amino coupler is intended to refer to aminophenyl, aminonaphthyl, etc., radicals, and substituted derivatives thereof; and the expressions radical of a heterocyclic aromatic coupler, radical of an aliphatic activated methylene coupler and radical of an alicyclic activated methylene coupler are to be similarly construed.

The novel dye developers of this invention may be prepared by diazotizing a compound of the formula:

'(C) Iu ZIv Y-S O z-A r- (N=N-X a) m-NH;

wherein Y, Z, m, u, v and X have the same meaning as above, and coupling the diazotized Compound C into the desired coupling components providing X The compounds of Formula C, wherein m is 0, e.g., p-aminophenylsulfonyl-hydroquinone, may be prepared according to the procedure of Burton and Hoggarth, JCS, 1945, page 468. The hydroxyl groups may be protected during the diazotization and coupling reactions by the use of protective derivatives, e.g., acyl groups, of said hydroxyl groups. Such acylated compounds may be prepared according to the procedure disclosed and claimed in US. Patent No. 3,019,254, issued January 30, 1962, to Milton Green and Helen P. Husek. The monoazo intermediates may be made as disclosed herein and may be employed without removal of such protective groups in subsequent diazotization and coupling steps.

The preferred compound within the group represented by Formula C is:

p-aminophenylsulfonyl-hydroquinone and 1,5- diaminonaphthalene.

Where the coupling component is a phenolic coupler, and particularly a naphthol, it has been found that coupling ortho to the hydroxyl group gives a dye developer of superior color properties.

As examples of suitable dye developers Within the scope of this invention, mention may be made of the 1phenyl-3-methyl-4- [p- (hydroquinonylsulfonyl) phenylazo] irpyrazolone 4-1nethoxy-2- [p- (hyroquimlaln lslulfonyl) -phenylazo The coupling component employed to provide the radical X is preferably a coupler containing a diazotizable amino group. It is to be understood, however, that one may employ a coupler having a group convertible to a diazotizable amino group, e.g., a nitro group. The diazotizable amino group may be on a nucleus other than the one substituted by the azo grouping.

As examples of additional coupling components which may be used to provide X mention may be made of:

4-benzyl-1-naphthol 4-methyl-1-naphthol 4-methoxy-a-naphthylamine 4-acetamido-m-naphthylamine Phenol Aniline 1,5 -naphthalenediamine p-Cresol l-hydroxyanthracene l-hydroxy-Z-naphthanilide Diketohydrindene Mal-ononitrile Acetoacetanilide The novel dye developers within the scope of this invention give generally brighter dye images in the diffusion transfer process than many other azo dye developers. This unobvious property may be illustrated by the compound of Formula II which compound is a brighter dye than 2 [p (2',5 dihydroxyphenethyl) phenylazo]- 4-methoxy-1-naphthol employing the same azo coupler, disclosed and claimed in the copending application of Elkan R. Blount, Milton Green and Howard G. Rogers, Serial No. 144,816, filed October 18, 1961, now US. Patent 3,134,672, issued May 26, 1964, and also fades to a magenta shade that is brighter than the shade of the above-mentioned 2- [p- 2',5'-dihydroxyphenethyl -phenyl azo1-4-methoxy-1-naphthol after both dyes have been exposed to accelerated fading conditions for an equal period. It should also be noted that the muddy or dull appearance frequently found in dye developers such as the above-identified 2- [p-(2,5-dihydroxyphenethyl)-phenylazo]-4-methoxy-l-naphthol after such accelerated fading tests is not found in the dye developers of this invention. In other words, the dye developer of Formula II fades to shades of magenta Without the appearance of undesirable dull color characteristics which may be described as muddying, but rather retains the brightness characteristics originally found in the dye before fading.

The dye developers of this invention are pH sensitive since the sulfonyl linking group is not an insulating group and therefore care must be taken in the utilization of such dye developers to provide a pH which will afford the desired color.

The dye developers of this invention are less active dye developers than, for example, the dye developers of the above-mentioned application Serial No. 144,816, and are therefore useful where such a diminished degree of activity is desired.

The following examples of the preparation of dye developers within the scope of this invention by diazotizing and coupling compounds within Formula C are given for the purposes of illustration only.

Example 1 2.9 g. of p aminophenylsulfonyl hydroquinone-0,0- diacetate (0.0083 moi) is dissolved in 20 cc. of water and 25 cc. of glacial acetic acid by heating. The mixture is cooled to about C. and 0.66 cc. of 12.5 N hydrochloric acid (0.0083 moi) is added. The resultant mixture is cooled in an ice bath and diazotized with sodium nitrite. The resulting diazo slurry is added, with constant stirring, to a mixture of 1.4 g. of 1-phenyl-3-methyl-5- pyrazolone (0.008 mol), cc. of pyridine, 50 cc. of water, and 20 cc. of saturated sodium bicarbonate solution, concurrently with sufficient 10% sodium carbonate solution to maintain a pH of 7 to 8. The resulting slurry is stirred for about 2 hours at room temperature, filtered and Washed with water. The acetyl groups are removed by hydrolysis in vacuo with 3 g. of 85% potassium hy droxide, 10 cc. of water, 40 cc. of ethanol and heating for a few minutes on a steam bath. The resulting mixture is cooled, poured into a dilute hydrochloric acid solution and then filtered. The precipitate is purified by dissolving it in methyl cellosolve and reprecipitating with a 1% hydrochloric acid solution to yield 1.4 g. of 1-phenyl-3- methyl 4 [p (hydroquinonylsulfonyl) phenylaz0]- S-pyrazolone [Formula I], M.P. 235 to 237 C. The absorption spectrum of this product exhibits a k of 390 my in acetone, e=27,000.

Example 2 4 g. of p aminophenylsulfonyl hydroquinone 0,0- diacetate (0.0115 mol) is dissolved in 30 cc. of glacial acetic acid and 0.92 cc. of 12.5 N hydrochloric acid by heating to a boil. The mixture is cooled in an ice bath and diazotized with sodium nitrite. The resultant clear diazo solution is added to 30 cc. of an ice Water mixture and the resultant diazo slurry is added with constant stirring, to a mixture of 1.4 g. of 4-methoxy1-naphthol (0.008 mol), 70 cc. of acetone, 40 cc. of saturated sodium bicarbonate solution, 20 cc. pyridine, and 40 cc. of Water, concurrently with sufficient 10% sodium carbonate to maintain a pH of 7 to 8. The resulting slurry is stirred for about 2 hours at room temperature, diluted with water and the mixture decanted yielding a gum product. The acetyl groups are removed by hydrolysis in vacuo with 4 g. of 85% potassium hydroxide, cc. of ethanol, 15 cc. of water and heating for a few minutes on a steam bath. The resulting mixture is cooled, poured into a dilute hydrochloric acid solution and then filtered. The resulting precipitate is purified by dissolving it in a methyl Cellosolve solution and reprecipitating with Water to yield 1.1 g. of 4 methoxy 2 [p (hydroquinonylsulfonyl)- phenylazo]-l-naphtho1 [Formula II], M.P. 184 to 188 C. The absorption spectrum of this product exhibits a A of 516 m l in acetone, e:20,500.

In the following examples all parts are given by weight except where otherwise noted, and all operations involving light-sensitive materials are carried out in the absence of actinic radiation. These examples are intended to be illustrative only of the photographic use of the dye developers and should not be construed as limiting the invention in any Way.

Example 3 A photosensitive element is prepared by coating a gelatin-coated film base with a solution containing 3% of 1- phenyl 3 methyl 4 [p (hydroquinony1sulfonyl)- phenylazo]5-pyrazolone [Formula I as prepared in Example 1], in a 4% solution of cellulose acetate hydrogen phthalate in a 50:50 mixture, by volume, of acetone and tetrahydrofuran. After this coating has dried, a silver iodobromide emulsion is applied.

This photosensitive element is exposed and processed by spreading an aqueous liquid processing composition comprising:

Percent Sodium carboxymethyl cellulose 6.0 1-phenyl-3-pyrazolidone 0.2 Sodium hydroxide 5.0 Potassium bromide 0.5

between said photosensitive element and an image-receiving element as said elements are brought into superposed relationship. The image-receiving element comprises a cellulose-coated baryta paper which has been coated with a solution comprising 10% nylon type F8 (trade name of E. I. du Pont de Nemours & Co., Wilmington, Delaware, for N-methoxy-methyl polyhexamethylene adipamide) in 80% aqueous isopropanol. After an imbibition period of approximately one minute, the image-receiving element is separated and contains a yellow positive dye image of the photographed subject.

Example 4 A photosensitive element is prepared similar to that described in Example 3 using 3% of 4-methoxy-2-[p- (hydroquinonylsulfonyl) phenylazo] 1 naphthol [Formula II as prepared in Example 2]. Exposure and processing with a liquid processing composition and image-receiving element similar to those described in Example 3 give a magenta positive dye image.

The dye developers of this invention are also useful in integral multilayer photosensitive elements for use in multicolor diffusion transfer processes. As an example of such photosensitive elements, mention may be made of the photosensitive elements disclosed and claimed in the copending U.S. application of Edwin H. Land and Howard G. Rogers, Serial No, 565,135, filed February 13, 1956, wherein at least two selectively sensitized photosensitive strata are superposed on a single support and are processed, simultaneously and without separation, with a single common image-receiving element. A suitable arrangement of this type comprises a support carrying a red-sensitive silver halide emulsion stratum, a green-sensitive silver halide emulsion stratum and a blue-sensitive silver halide emulsion stratum, said emulsions having associated therewith, respectively, a cyan dye developer, a magenta dye developer and a yellow dye developer. In one of the preferred embodiments of photosensitive elements of this type, the dye developers are disposed in separate alkali-permeable layers behind the photosensitive silver halide emulsion stratum with which they are associated.

The photosensitive elements within the scope of this invention may be used in roll film units which contain a plurality of photosensitive frames. The photosensitive elements of this invention are especially useful in composite roll film intended for use in a Polaroid Land Camera, sold by Polaroid Corporation, Cambridge 39, Massachusetts, or a similar camera structure such, for example, as the camera forming the subject matter of U.S. Patent No. 2,435,717, issued to Edwin H. Land on February 10, 1948. In general, such composite roll films comprise a photosensitive roll, a roll of image-receiving material and a plurality of pods containing an aqueous alkaline processing solution. The rolls and pods are so associated with each other that, upon processing, the photosensitive element may be superposed on the imagereceiving element and the pods may be ruptured to spread the aqueous alkaline processing solution between the superposed elements. The nature and construction of the pods used in such units are well known to the art. See, for example, U.S. Patents Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land.

It will be noted that the liquid processing composition may contain one or more auxiliary or accelerating silver halide developing agents, such as p-methylaminophenol (Metol); 2,4-diaminophenol (Amidol); benzylaminophenol; hydroquinone; a substituted hydroquinone such as toluhydroquinone, phenylhydroquinone, or 4-methylphenylhydroquinone; or a 3-pyrazolidone such as 1-phenyl-3- pyrazolidone. These silver halids developing agents are substantially colorless, at least in their unoxidized form. It is possible that some of the dye developer oxidized in exposed areas may be oxidized by an energy transfer reaction with oxidized auxiliary developing agent.

In addition, development may be effected in the presence of an onium compound, particularly a quaternary ammonium compound, in accordance with the processes disclosed and claimed in the copending application of Milton Green and Howard G. Rogers, Serial No. 50,851, filed August 22, 1960, now U.S. Patent 3,173,786.

The dye developers of this invention may be used also in conventional photographic processes, such as tray or tank development of conventional photosensitive films, plates or papers to obtain black and white, monochromatic or toned prints or negatives. By way of example, a developer composition suitable for such use may comprise an aqueous solution of approximately 1-2% of the dye developer, 1% sodium hydroxide, 2% sodium sulfite and 0.05% potassium bromide. After development is completed, any unreacted dye developer is washed out of the photosensitive element, preferably with an alkaline washing medium or other medium in which the unreacted dye developer is soluble. The expression toned is used to designate photographic images wherein the silver is retained with the precipitated dye, whereas monochromatic is intended to designate dye images free of silver.

It should be noted that the dye developers of this medium are self-sufficient to provide the desired color image and do not depend upon coupling reactions to produce the desired color. They thus provide a complete departure from conventional photographic color processes in which the color is produced by a coupling reaction between a color former or coupler and the oxidized developing agent, as well as so-called auto coupling processes in which color is obtained by a reaction of the oxidized developing agent with unoxidized developing agent.

It will be apparent that, by appropriate selection of the image-receiving element from among suitable knovm opaque and transparent materials, it is possible to obtain either a colored positive reflection print or a colored positive transparency. Likewise, the inventive concepts herein set forth are adaptable for multicolor work by the use of special photographic materials, for example, film materials of the type containing two or more photosensitized elements associated with an appropriate number of imagereceiving elements and adapted to be treated with one or more liquid processing compositions, appropriate dye developers suitable to impart the desired subtractive colors being incorporated in the photosensitized elements or in the liquid processing compositions. Examples of such photographic materials are disclosed in U.S. Patent No. 2,647,049 to Edwin H. Land.

As examples of useful imag e-receiving materials, mention may be made of nylon, e.g., N-methoxymethyl-polyhexamethylene adipamide, polyvinyl alcohol, and gelatin, particularly polyvinyl alcohol or gelatin containing a dye mordant such as poly-4-vinylpyridine. The image-receiving element also may contain a development restrainer, e.g., 1-phenyl-5-mercaptotetrazole, as disclosed in the copending application of Howard G. Rogers and Harriet W.

Lutes, Serial No. 50,849, filed August 22, 1960.

The dye developers herein set forth are also useful in the formation of colored images in accordance with the photographic products and processes described and claimed in U.S. Patent No. 2,968,554, issued to Edwin H. Land on January 17, 1961.

The novel compounds herein disclosed are also suitable for use as dyes for textile fibres, such as nylon.

In the preceding portions of the specification the expression color has been frequently used. This expression is intended to include the use of a plurality of colors to obtain black.

My copending U.S. application, Serial No. 230,288, filed concurrently herewith, claims the novel chemical compounds of this invention.

Since certain changes may be made in the above products, compositions and processes without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A process for forming a photographic image in color, comprising developing an exposed silver halide emulsion in the presence of an aqueous alkaline solution comprising a dye developer of the formula:

wherein Ar is an aryl nucleus; In is an integer from 0 to 1, inclusive; p is an integer from 1 to 2, inclusive; Y is a dihydroxyphenyl silver halide developing radical; and X and X each is the radical of an azo dye coupler linked to said N=N group and completing said azo dye, to thereby provide a predetermined imagewise distribution of unoxidized dye developer, and transferring at least a part of said imagewise dye developer by imbibition to an 9 image-receiving layer in superposed relationship with said silver halide emulsion to impart a dye image to said imagereceiving layer.

2. A process as defined in claim 1 wherein said dye developer is disposed, prior to exposure, in the photosensitive element comprising said exposed silver halide emulsion, and the solution containing said dye developer is formed by permeating said photosensitive element with an aqueous alkaline liquid capable of solubilizing said dye developer.

3. The process as defined in claim 1 whereby said liquid is introduced by being spread in a substantially uniform layer as said photosensitive element and image-receiving layer are brought into superposed relationship.

4. The process as defined in claim 1 wherein said liquid contains a thickener for increasing viscosity and for facilitating the spreading thereof between said photosensitive element and said image-receiving layer.

5. A process as defined in claim 1 wherein X is a phenolic azo coupler radical.

6. A process as defined in claim 1 wherein X, is an aromatic amino azo coupler radical.

7. A process as defined in claim 1 wherein X is a heterocyclic aromatic azo coupler radical.

8. A process as defined in claim 1 wherein X is selected from the group consisting of aliphatic and alicyclic activated methylene azo coupler radicals.

9. A process as defined in claim 1 wherein said aqueous alkaline solution contains a silver halide developing agent.

10. A process as defined in claim 9 wherein said silver halide developing agent is l-phenyl-S-pyrazolidone.

11. A process as defined in claim 1 wherein said dye developer is 1 phenyl 3 methyl 4 [p (hydroquinonylsulfonyl) -phenylazo] -5-pyrazolone.

12. A process as defined in claim 1 wherein said dye developer is 4 methoxy 2 [p (hydroquinonylsulfonyl -phenylazo] 1 -naphthol.

13. A process of developing an exposed silver halide emulsion which comprises treating said emulsion for a time sufiicient to develop with an aqueous alkaline solution comprising a compound of the formula:

wherein Ar is an aryl nucleus; in is an integer from to l, inclusive; p is an integer from 1 to 2, inclusive; Y is a dihydroxyphenyl silver halide developing radical; and X and X each is the radical of an azo dye coupler linked to said -N=N- group and completing said azo dye.

14. A process as defined in claim 13 wherein X is a phenolic azo coupler radical.

15. A process as defined in claim 13 wherein X, is an aromatic amino azo coupler radical.

16. A process as defined in claim 13 wherein X is a heterocyclic aromatic azo coupler radical.

17. A process as defined in claim 13 wherein X is selected from the group consisting of aliphatic and alicyclic activated methylene azo coupler radicals.

18. A process as defined in claim 13 wherein said aqueous alkaline solution contains a second silver halide developing agent.

19. A process as defined in claim 18 wherein said second silver halide developer is a B-pyrazolidone.

20. A process as defined in claim 18 wherein said second silver halide developer is l-phenyl-3-pyrazolidone.

21. A process as defined in claim 13 wherein said compound is 1 phenyl 3 methyl 4 [p (hydroquinonylsulfonyD-phenylazo] -5- pyrazolone.

22. A process as defined in claim 13 wherein said compound is 4 methoxy 2 [p (p-hydroquinonylsulfonyl)- phenylazo] l -naphthol.

23. A photographic product comprising a support, a silver halide emulsion in a layer carried by said support,

10 and a dye developer in a layer carried by said support, on the same side thereof as said silver halide emulsion, said dye developer being a compound of the formula:

[Y-s0zAiN=N- X.-N=N- ,,Xs

wherein Ar is an aryl nucleus; n is an integer from 0 to 1, inclusive; p is an integer from 1 to 2, inclusive; Y is a dihydroxyphenyl silver halide developing radical; and X and X each is the radical of an azo dye coupler linked to said N=N group and completing said azo dye.

24. A photographic product as defined in claim 23, wherein said dye developer is in a layer positioned between said support and said layer containing said silver halide emulsion.

25. A photographic product as defined in claim 23 wherein X is a phenolic azo coupler radical.

26. A photographic product as defined in claim 23 wherein X, is an aromatic amino azo coupler radical.

27. A photographic product as defined in claim 23 wherein X is a heterocyclic aromatic azo coupler radical.

28. A photographic product as defined in claim 23 wherein X is selected from the group consisting of aliphatic and alicyclic activated methylene azo coupler radicals.

29. A photographic product as defined in claim 23 wherein said compound is l-phenyl-3-methyl-4-[p-(hydroquinonylsulfonyl)-phenylazo]-5-pyrazolone.

30. A photographic product as defined in claim 23 wherein said compound is 4-methoxy-2-[p-(hydroquinonylsulfonyl) -phenyl] -l-naphthol.

31. A photographic composition comprising an aqueous alkaline solution of a colorless silver halide developing agent and a dye developer of the formula:

wherein Ar is an aryl nucleus; 11 is an integer from 0 to 1, inclusive; p is an integer from 1 to 2, inclusive; Y is a dihydroxyphenyl silver halide developing radical; and X; and X, each is the radical of an azo dye coupler linked to said N=N group and completing said azo dye.

32. A photographic developer composition as defined in claim 30 wherein said colorless silver halide developing agent is a 3-pyrazolidone.

33. A photographic developer composition as defined in claim 30 wherein said 3-pyrazolidone is 1-phenyl-3- pyrazolidone.

34. A photographic developer composition as defined in claim 30 wherein X is a phenolic azo coupler radical.

35. A photographic developer composition as defined in claim 30 wherein X is an aromatic amino azo coupler radical.

36. A photographic developer composition as defined in claim 30 wherein X is a heterocyclic aromatic azo coupler radical.

37. A photographic developer composition as defined in claim 30 wherein X is selected from the group consisting of aliphatic and alicyclic activated methylene azo coupler radicals.

38. A photographic developer composition as defined in claim 30 wherein said dye developer is l-phenyl-3-methyl- 4- [p-(hydroquinonylsulfonyl -phenylazo -5-pyrazolone.

39. A photographic developer composition as defined in claim 30 wherein said dye developer is 4-methoxy-2- [p- (hydroquinonylsulfonyl -phenylazo] l-naphthol.

References Cited by the Examiner UNITED STATES PATENTS 2,983,606 5/1961 Rogers 9629 FOREIGN PATENTS 554,212 7/ 1957 Belgium.

NORMAN G. TORCHIN, Primary Examiner. 

1. A PROCESS FOR FORMING A PHOTOGRAPHIC IMAGE IN COLOR, COMPRISING DEVELOPING AN EXPOSED SILVER HALIDE EMULSION IN THE PRESENCE OF AN AQUEOUS ALKALINE SOLUTION COMPRISING A DYE DEVELOPER OF THE FORMULA: 